Heat Exchanger

ABSTRACT

The invention relates to a heat exchanger ( 1 ) having a plurality of tubes ( 4 ) and at least one box ( 3 ) that is closed by a bottom ( 2 ) provided with openings ( 6 ), at least one end ( 5 ) of the tubes ( 4 ) leading to said box. The invention is characterized in that the bottom ( 2 ) is provided with cams ( 7 ) and/or beads (7′)

The invention relates to a heat exchanger as per the preamble of claim 1.

A section through a conventional heat exchanger is illustrated in FIG. 36. Here, a tank is closed off by a plate which has a plurality of openings which are formed by rim holes which extend in the direction of the tank and project into the ends of flat tubes. The plate has a peripheral bead into which the end of the tank projects, with a sealing ring being arranged so as to provide sealing between the end of the tank and the plate. The plate is attached to the tank for example by means of corrugated slot flanging. A heat exchanger of said type leaves something to be desired.

EP 0 990 868 A2 discloses a heat exchanger having a plurality of tubes whose ends plug into rim holes around the opening in the tube plates, which rim holes point toward the heat exchanger network, the cross section of which rim holes is arched inward, and which rim holes are metallically connected therein in a fluid-tight manner, with different heat-exchanging media flowing through the tubes and around the tubes. Here, the tube ends extend to below the level of the tube plate surface. In addition, the tube ends form, with the rim holes, an encircling contact face which is adjoined at both sides by a solder gap between the tube and the rim hole. In this known embodiment, too, the plate has a peripheral bead into which the end of the tank projects, with a sealing ring being arranged between the end of the tank and the lowest region of the bead.

Proceeding from said prior art, it is an object of the invention to provide an improved heat exchanger.

Said object is achieved by means of a heat exchanger having the features of claim 1. Advantageous embodiments are the subject matter of the subclaims.

In accordance with the invention is a heat exchanger having a plurality of tubes and having at least one tank which is closed off by means of a plate which is provided with openings and into which the at least one end of the tubes opens out, with the plate having a plurality of individual lobes and/or beads. The lobes are preferably formed in the plate regions between the tubes, that is to say in the region of the webs between the openings which hold the tubes, and at the longitudinal-side ends of the plate. In this way, the lobes can assume the function of the peripheral bead which is dispensed with according to the invention, wherein the heat exchanger can be of narrower design, since the lobes which replace the peripheral bead are indented between the openings or the tubes. Here, the plate—as a result of the bead being dispensed with—is of shell-like design and of smaller design than in conventional heat exchangers.

The length of the lobes is preferably a maximum of 50%, in particular a maximum of 45%, a maximum of 40% and particularly preferably a maximum of 25% of the length of the openings which hold the tubes. Overall, the length of the individual lobes is preferable 5 to 25 mm, particularly preferably 10 to 15 mm.

Alternatively, the lobes can be designed so as to run continuously over the entire length of the webs, as well as at the edge regions, and parallel to the webs, with the lobes in this embodiment being referred to in the following as beads. Said beads also offer the same advantages as the previously mentioned lobes over the known peripheral beads.

The lobes and/or beads rise in the longitudinal extent of the tubes toward the tank, that is to say away from the heat exchanger network. On account of the bead being dispensed with, the plate additionally has an improved fatigue strength under alternating pressure loading. Here, the lobes and/or beads serve, with their ends which point toward the plate edge, to hold the tank.

The lobes and/or beads are preferably formed by means of a shaping process, in particular in a working step with the production of the rim holes and the bending of the sides. Here, the plate-edge-side end of said rim holes is formed so as to absorb the forces which occur during assembly and which press the tank together, so that a collapse of the tank is avoided and therefore the impermeability of the connection of the tank and plate can be ensured.

The lobes and/or beads preferably have a constant height over their entire length. The edge-side end of the lobes and/or beads can however also be of higher design then the inward-pointing end, which can if appropriate also end flat.

The openings which receive the tubes are preferably formed as rim holes. Said rim holes preferably extend in the direction of the tubes, that is to say away from the tank.

Here, the tubes preferably end flush with, or if appropriate also project slightly beyond, the rim holes. The rim holes can however also be designed corresponding to EP 0 990 868 A2.

The plate is preferably of planar design—with the exception of the lobes, beads and rim holes—and the longitudinal and narrow-side ends of the plate are preferably bent around, adjacent to a planar region, at an angle of 80 to 90° in the direction of the tank, with a sufficient bending radius being provided.

The tank preferably has a lug which protrudes in the direction of the plate and which is formed spaced apart from the periphery of the tank. The provision of a lug of said type is in principle also possible in the case of an encircling bead. A seal is preferably arranged at the outer peripheral side of the lug, wherein said seal can be a sealing ring or a seal which is injection-molded onto the tank. The sealing ring can in this case be either mounted onto the tank or mounted into the plate, and therefore assembly can be simplified. In the case of a seal which is injection-molded on, the assembly step can be dispensed with.

In one advantageous embodiment, the seal has ear-like retaining elements which can be or are hooked into cutouts provided at the corners of the plate. In this way, the seal can be particularly advantageously assembled or hooked into the provided cutouts, or can be particularly advantageously hooked into the provided cutouts.

The height of the lug preferably corresponds approximately to the height of the lobes and/or beads, so that the lug additionally protects the edge of the tank against damage.

The lobes or beads, in interaction with the lug, limit the maximum deformation by forces which act laterally on the plate in particular during the process of the assembly. Here, the lug and lobe or bead also come into contact with one another if appropriate.

According to one preferred embodiment, the tank has, in the vicinity of its plate, on its inner peripheral side, inwardly extending ribs or projections. In this way, the lobes and/or beads can be moved further inward into the plate. Here, the local material reinforcement of the plate-side part of the tank is designed such that the tubes are not blocked, so that the flow is not hindered. The ribs or projections preferably bear against the lobes and/or beads, in order to absorb the forces which occur in particular during the assembly. Here, the openings for the tubes preferably extend in between the ribs or projections, so that the heat exchanger can be of narrower design than conventional heat exchangers.

In order that the flow is not adversely affected and additionally that the weight of the tank is not excessively increased, the height of the ribs or projections preferably reduces in the direction into the tank.

The invention is explained in more detail below on the basis of five exemplary embodiments, in part with reference to the appended drawing, in which:

FIG. 1 shows a detail side view of a heat exchanger according to the first exemplary embodiment, with the tank partially indicated,

FIG. 2 shows a section along the line A-A in FIG. 1,

FIG. 3 shows a section along the line C-C in FIG. 1,

FIG. 4 shows a plan view of a plate from FIG. 1 from the direction of the indicated tank,

FIG. 5 shows a section along the line D-D in FIG. 4,

FIG. 6 shows a section along the line E-E in FIG. 4,

FIG. 7 shows a side view of the heat exchanger from FIG. 1, with the tank partially illustrated,

FIG. 8 shows a perspective view of the heat exchanger from FIG. 1, with the tank partially illustrated,

FIG. 9 shows a perspective view of the plate,

FIG. 10 shows a view of the plate from another perspective,

FIG. 11 is a perspective detail illustration of a corner region of the plate,

FIG. 12 shows a perspective view of the heat exchanger from FIG. 1, with an illustration of the base region of the tank,

FIG. 13 shows another perspective view of the heat exchanger from FIG. 1 with an illustration of the base region of the tank,

FIG. 14 is a detail illustration of a heat exchanger according to the second exemplary embodiment, with the tank illustrated in section,

FIG. 15 shows a section along line A-A in FIG. 14,

FIG. 16 shows a perspective view of a plate according to the third exemplary embodiment,

FIG. 17 shows a plan view of the plate from FIG. 16,

FIG. 18 is a detail section illustration along the line A-A in FIG. 17,

FIG. 19 is a detail section illustration along the line B-B in FIG. 17,

FIG. 20 is a detail section illustration along the line C-C in FIG. 17,

FIG. 21 is a detail section illustration along the line D-D in FIG. 17, with the left-hand part illustrating the section profile through a flat tube, and the right-hand part illustrating the section profile through a bead, in each case in the region of the tank wall and without the illustration of a sealing element,

FIG. 22 shows a side view of the plate from FIG. 16,

FIG. 23 shows another side view of the plate from FIG. 16,

FIG. 24 is a detail section illustration along the line F-F in FIG. 17, in the assembled but not yet fixedly connected state of the plate and tank,

FIG. 25 shows a schematic detail side view of a heat exchanger with a plate according to the fifth exemplary embodiment,

FIG. 26 shows a section through the plate and a part of a tank, which has been placed thereon, along the line A-A in FIG. 25,

FIG. 27 shows a section through the plate and a part of a tank, which has been placed thereon, along the line B-B in FIG. 25,

FIG. 28 shows a perspective view of the plate from FIG. 25 from the direction of the tank,

FIG. 29 shows a perspective view of the plate from FIG. 25 from the direction of the flat tubes,

FIG. 30 is a detail perspective illustration of the heat exchanger from FIG. 25 with a plate placed thereon and a sealing ring mounted in,

FIG. 31 shows a plan view of the plate of the heat exchanger from FIG. 25 with a sealing ring mounted in,

FIG. 32 shows a section through the plate with the tank, sealing ring and flat tubes, along the line C-C in FIG. 31,

FIG. 33 shows a section through the plate with the tank, sealing ring and flat tubes, along the line D-D in FIG. 31,

FIG. 34 shows a section through the plate with the tank, sealing ring and flat tubes, along the line E-E in FIG. 31,

FIG. 35 shows a side view of the heat exchanger from FIG. 25, and

FIG. 36 shows a section through a conventional heat exchanger.

FIG. 1 shows a heat exchanger 1, in the present case a compact charge air cooler, composed of two tanks 3 which are closed off by plates 2 and of a plurality of tubes 4 which extend between the tanks 3. The tubes 4 are embodied as flat tubes and project with their ends 5 into openings 6, which are embodied as rim holes corresponding to the outer dimensions of the tubes 4, in the plate 2. Here, the rim holes point in the direction of the tubes 4, with the tubes 4 ending in each case approximately flush with the face, which faces toward the corresponding tank 3, of the plates 2 in the present case (cf. FIG. 2).

The plate 2, which is formed as a sheet metal punched and bent part, also has a plurality of elevations in the form of lobes 7 which extend in the direction of the tank 3, that is to say rise above the plate base plane B. In the present case, the lobes 7 are produced by means of a shaping process. Here, in each case two first lobes 7 a are arranged in each case in the region of the ends of the webs between two openings 6, and three second lobes 7 b are arranged at the narrow-side end of the plate 2 (cf. FIG. 4).

The length of the first knob 7 a and also of the second knob 7 b is approximately 22% of the length of the openings 6, that is to say of the rim holes and therefore of the (greater) width of the flat tubes, with the first knobs 7 a in the present case having a length of 15 mm.

The longitudinal-side and narrow-side ends of the plate 2 are, in the assembled state which is not illustrated, to be bent around at right angles with respect to the tank 3, with cutouts being provided in each case at the corners 8 of the plate 2. Provided at the ends are a plurality of slots 9 which serve for the connection of the plate 2 and tank 3 by means of the known corrugated slot flanging, that is to say individual material parts of the plate 2 engage behind the corresponding end regions, which are provided with a shoulder 10, of the tank 3. As can be seen for example from FIG. 9, the slots 9 are in the present case arranged in each case at the height of the openings 6 (longitudinal side) and of the second lobes 7 b (narrow side).

The plate-side end of the tank 3 is provided with a peripheral lug 11 which is formed on the inner peripheral side and extends in the direction of the plate 2, so that a shoulder 12 for holding a sealing ring 13 is formed (see FIGS. 2 and 3). According to the present exemplary embodiment, the sealing ring 13 is mounted onto said shoulder 12, with the mounting taking place during the assembly and before the tank 3 is placed onto the plate 2. The sealing ring 13 is in the present case a sealing ring 13 with a circular profile, though other profiles, in particular oval or rectangular profiles (flat seal) are also possible.

It is also alternatively possible for the sealing ring 12 to be mounted onto the plate 2 by means of retaining elements which are formed on the sealing ring 12 and are clamped into cutouts which are provided at the corners 8 of the plate 2. This particularly preferred embodiment is explained in more detail with reference to the fifth exemplary embodiment which is described at a later point.

According to a variant which is not illustrated in the drawing, the seal is formed so as to be injection-molded directly onto the tank 3 in the shoulder 12, so that incorrect assembly of the sealing ring can be avoided.

In all three cases, after the positioning or formation of the sealing ring, the tank 3 is placed on and the seal is compressed. According to the present exemplary embodiment, the closure then takes place by means of corrugated slot flanging, with the lobe 7 which is integrated into the plate 2 serving to support the tank 3 against the forces which act as a result of the closure device, so that a collapse of the tank 3 and associated permeability is avoided.

According to the second exemplary embodiment which is illustrated in FIGS. 14 and 15, which—where not expressly mentioned—corresponds to the previously described first exemplary embodiment, for which reason identical and equivalent elements are provided with the same reference symbols, battlement-like ribs 14 are formed on the inner peripheral side of the tank 3, which ribs 14 interact with the first lobes 7 a which are offset further rearward in the longitudinal direction of the webs between the openings 6. Here, the ribs 14 on the tank 3 extend to the plate-side end of the lug 11. In the present case, the ribs 14 are designed so as to reduce in height above the first lobes 7 a.

FIGS. 16 to 24 illustrate a plate 2 according to the third exemplary embodiment. Here—in contrast to the lobes 7 a and 7 b of the two previously described exemplary embodiments—lobes, referred to in the following as beads 7′, which extend over substantially the entire width of the plate 2, are formed with a substantially continuous cross-sectional profile (see FIG. 18), which beads 71 are in the present case formed by means of shaping, that is to say corresponding to the lobes 7 a and 7 b.

Here, the webs between the openings 6 have edges 6′ (rim holes) which run in the direction of the flat tubes which are to be introduced, approximately perpendicularly to the plate 2, which edges 6′ have an arcuate transition in the direction of the plate base plane B, that is to say of the plate 2 without beads 7′ which are continuous in the web longitudinal direction.

The bead 7′ is subsequently formed, with the bead 7′ likewise having arcuate transitions. In the present case, the cross section of each web has three radii whose central points are arranged within the web, and two radii whose central points are arranged outside the web, that is to say the transitions are in each case formed as circular-arc sections, though the curvature profile of the individual transitions can also vary.

In each case one continuous bead 7′ is also arranged at the narrow-side edge regions of the plate 2 instead of the three lobes 7 b according to the first exemplary embodiment.

If the plate base plane B is not formed by a face as in the first two exemplary embodiments, it is defined by the turning point of the curvature profiles of rim holes and beads 7′, as indicated in the detail view X of FIG. 18.

According to the present exemplary embodiment, the flat tube ends of the flat tubes 4 which are arranged in the openings between the webs (see FIG. 24) project, in the assembled and soldered state, slightly beyond the plate base plane B—that is to say the plane which has the plate without formed beads—but it is also possible for said flat tube ends to end flush with the plate base plane B or to project to the end of the beads and if appropriate also beyond.

The tank 3 is attached in the way described in the first exemplary embodiment.

According to a fourth exemplary embodiment which is not illustrated in the drawing, the lobes are designed such that the narrowing ends of the lobes substantially directly adjoin one another in the central longitudinal plane of the plate, that is to say the two lobes are approximately designed as a single, continuous lobe.

According to the fifth exemplary embodiment illustrated in FIGS. 25 to 35, a heat exchanger 1, again a charge air cooler, has two tanks which are closed off by plates 2, and a plurality of tubes 4 which extend between the tanks 3. The tubes 4 are embodied as flat tubes, and corrugated fins are arranged between two tubes. The tubes 4 project with their ends 5 into openings 6, which are embodied as rim holes corresponding to the outer dimensions of the tubes 4, in the plates 2. Here, the rim holes point in the direction of the tubes 4, with the tubes 4 in each case projecting slightly beyond the plates 2 in the present case (see FIG. 32).

The plate 2, which is formed as a sheet metal punched and bent part, also has a plurality of elevations in the form of lobes 7 which extend in the direction of the tank 3, that is to say rise above the plate base plane B. In the present case, the lobes 7 are produced by means of a shaping process by means of punches with a trapezoidal or triangular cross section. Here, in each case two first lobes 7 a are arranged in each case in the region of the ends of the webs between two openings 6. In addition, in each case four second lobes 7 b, which are arranged in a row and, in the present case, are of corresponding design to one another, are provided at the narrow-side end of the plate 2 (cf. FIG. 28). The length of the first lobes 7 a and of the second lobes 7 b corresponds to one another, but their design differs, that is to say their groove shape. The first lobes 7 a have an approximately V-shaped design of substantially constant height, while the second lobes 7 b have a more U-shaped profile which is rounded off toward the center of the plate and, in the outward direction, is of steeper design and has a substantially constant height.

The longitudinal-side and narrow-side ends of the plate 2 are, in the assembled state, to be bent around at right angles with respect to the tank 3, with cutouts being provided in each case at the corners 8 of the plate 2. The cutouts serve to receive on a sealing ring 13 which is mounted into the plate 2 and which has, at its four corners, ear-shaped retaining elements 13′ which are connected in one piece with the sealing ring 13 by means of a web. In contrast to sealing rings which are arranged on conventional plates and which are placed under tension into an outer peripheral groove and are clamped in by the tank, the sealing ring 13 lies on a planar face in the plate base plane B, with said sealing ring 13 being clamped in a rectangular shape in a defined manner by the retaining elements 13′ which are held in the cutouts so that good sealing can be ensured between the tank and the plate. The sealing ring 13 has, in the present case, a circular cross section, through in principle, some other cross section can also be provided, for example a rectangular cross section.

Provided in the ends of the plates 2 are a plurality of slots 9 which serve for the connection of the plate 2 and tank 4 by means of the known and corrugated slot flanging.

The length of the first knobs 7 a and also of the second knobs 7 b is approximately 20% of the length of the openings 6, that is to say of the rim holes and therefore of the (greater) width of the flat tubes, with the first knobs 7 a in the present case having a length of 10 mm.

Combinations of the above-described exemplary embodiments are of course possible, for example with lobes 7 according to the first exemplary embodiment and lobes 7′ according to the third exemplary embodiment being provided alternately on adjacent webs. It is likewise possible for only continuous lobes 7′ to be provided on the central webs and for lobes 7 to be provided on the outer webs. Likewise possible is a transition in the outward direction from continuous lobes 7′ to lateral lobes 7 which are separated by a web region which is substantially unshaped, that is to say, in the center, the design is carried out according to the third exemplary embodiment, then according to the fourth exemplary embodiment and, in the outward direction, according to the first exemplary embodiment, with the longitudinal extent of the lobes reducing in the outward direction. In the edge region, however, the lobes 7 which are formed separately do not differ from the continuous lobes 7′, so that no special adaptation of the tank to differently-designed web regions is necessary. 

1. A heat exchanger having a plurality of tubes and having at least one tank which is closed off by means of a plate which is provided with openings and into which the at least one end of the tubes opens out, wherein the plate has lobes and/or beads.
 2. The heat exchanger as claimed in claim 1, wherein the lobes and/or beads are formed in the plate regions between the tubes.
 3. The heat exchanger as claimed in claim 1, wherein the lobes and/or beads are formed at the longitudinal-side ends of the plate.
 4. The heat exchanger as claimed in claim 1, wherein the lobes and/or beads rise in the longitudinal extent of the tubes toward the tank.
 5. The heat exchanger as claimed in claim 1, wherein the lobes and/or beads are formed by means of a shaping process.
 6. The heat exchanger as claimed in claim 1, wherein the openings which receive the tubes are formed as rim holes which extend in the direction of the tubes.
 7. The heat exchanger as claimed in claim 6, wherein the tubes end flush with, or project slightly beyond, the rim holes.
 8. The heat exchanger as claimed in claim 1, wherein the plate is of planar design with the exception of the lobes and/or beads and rim holes, and the longitudinal and narrow-side ends of the plate are bent around at an angle of 80 to 90° in the direction of the tank.
 9. The heat exchanger as claimed in claim 1, wherein the tank has a lug which protrudes in the direction of the plate and which is formed spaced apart from the periphery of the tank.
 10. The heat exchanger as claimed in claim 9, wherein a seal is arranged at the peripheral side of the lug.
 11. The heat exchanger as claimed in claim 9, wherein the seal is mounted on or injection-molded on.
 12. The heat exchanger as claimed in claim 9, wherein the seal has ear-like retaining elements which can be hooked into cutouts provided at the corners of the plate.
 13. The heat exchanger as claimed in claim 9, wherein the height of the lug corresponds approximately to the height of the lobes and/or beads.
 14. The heat exchanger as claimed in claim 9, wherein the lug bears against the lobes or beads.
 15. The heat exchanger as claimed in claim 1 wherein the tank has, in the vicinity of its plate, on its inner peripheral side, inwardly extending ribs or projections.
 16. The heat exchanger as claimed in claim 15, wherein the ribs or projections bear against the lobes and/or beads.
 17. The heat exchanger as claimed in claim 15, wherein the height of the ribs or projections reduces in the direction into the tank.
 18. The heat exchanger as claimed in claim 15, wherein the openings for the tubes extend in between the ribs or projections. 